• Transactions of the Korean Society of Automotive Engineers
• /
• v.22 no.1
• /
• pp.65-70
• /
• 2014

An Integrated Dynamics Control system with four wheel Steering (IDCS) is proposed and analysed in this study. It integrates and controls steer angle of front and rear wheel simultaneously to enhance lateral stability and steerability. An active front steer (AFS) system and an active rear steer (ARS) system are also developed to compare their performances. The systems are evaluated during brake maneuver and several road conditions are used to test the performances. The results showed that IDCS vehicle follows the reference yaw rate and reduces side slip angle very well. AFS and ARS vehicles track the reference yaw rate but they can not reduce side slip angle. On split-${\mu}$ road, IDCS controller forces the vehicle to go straight ahead but AFS and ARS vehicles show lateral deviation from centerline.

• Journal of Auto-vehicle Safety Association
• /
• v.4 no.1
• /
• pp.5-11
• /
• 2012

This paper discusses the evaluation of the safety impact of the Adaptive Cruise Control (ACC) system in Korea. To evaluate the safety impact, this paper suggests an analysis method by using the test scenario and field operational test data. The test scenario is composed to represent the main component factor of the ACC system and ACC related accident situation such as rear-end collision, lane-change, and road-curvature, etc. Also, from the field operation test data, the system's potential to increase the safety can be measured ideally. Besides, field operational testdata was used to revise the expected safety impact value as Korean road conditions. By using the proposed evaluation method, enhanced safety impact of the ACC system can be estimated scientifically.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.04a
• /
• pp.711-714
• /
• 2001

As the life cycle of the vehicle become shorter, the method that reduce the development time of new model become more important. In this reason, the development of the simulator that provides similar environment with the actual vehicle road characteristics is increasing. In this paper, the multi-axis simulator is designed and analyzed by kinematic method. The simulator has a function simulating the 3 load elements; vertical, longitudinal, and lateral force respectively and simultaneously. The result of this paper can be used for developing the multi-axis simulator linkage.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.10 no.5
• /
• pp.110-116
• /
• 2011

Water on a road surface can lower the coefficient of friction of vehicle tires and it involves lots of risks. One way to prevent water from staying is to cut many "rain grooves" into the edges of the pavement parallel. Such grooves, however, can exert unwanted side forces, particularly on passenger tires, which cause "Groove Wander" making the drivers uncomfortable. The "Groove Wander" is somewhat related to vehicle geometry, but is more strongly related to interaction between road grooves and tire tread's longitudinal grooves. This thesis tries to examine principles to estimate "Groove Wandering" effect focusing on the design of longitudinal groove. Additionally, it studied how to reduce pipe resonance longitudinal grooves form in the contact patch.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.4
• /
• pp.93-98
• /
• 2020

Washboarding is a phenomenon in which a wavy shape occurs periodically and naturally on an unpaved road made of soil or gravel. This phenomenon causes high-frequency vibration of the traffic traveling on the road because of the height difference of the wave pattern, which may lead to vehicle failure. Consequently, associated research is needed concerning vehicle safety. Therefore, in this study, a numerical simulation was conducted using the discrete element method, which is often used for powder simulation. In contrast to previous studies, the results of this study demonstrate that washboarding can occur even in an environment of 1.5 m/s or less. However, the amount of washboarding is minimal. The study revealed that washboarding develops over time, such that sufficient development time is required before measurements are taken.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.698-704
• /
• 2007

Articulated vehicles which have a pivoting joint allowing the vehicle to rotate more easily are difficult to turn the curves because of their long length. In order to review operational safety, turning characteristics related to geometric design should be investigated when articulated vehicles run on the road which can be interfered with other vehicles. The vehicles to review the turning characteristics are the normal articulated bus in Seoul with FWS(front wheel steering) and new bimodal tram with AWS(all wheel steering). Steering characteristics and geometric design were investigated such as turning radius, offtracking, swept path width and swingout. The results were reviewed with respect to the standards of vehicle safety and road design.

• Annual Conference of KIPS
• /
• 2016.10a
• /
• pp.106-107
• /
• 2016

Vehicular Adhoc Network는 accident warning, road condition message와 같은 도로상의 정보를 vehicle-to-vehicle 통신을 통해 주어진 목적지까지 얼마나 빠르고 정확하게 전송하는 것이 주요 이슈이다. 무선 센서 네트워크의 많은 타입들 중에서 VANET 환경에 적합한 source 기반의 라우팅 프로토콜은 불안정한 이동 네트워크의 역할을 충실히 수행할 수 있다. Source 라우팅 기법들을 연구하는데 road topology와 map 정보가 사용되며, 본문에서는 도로의 상황과, 라우팅이 직접 수행되는 영역을 부분으로 나누어 각 영역에 속한 이동 노드를 파악하여 다중 경로 라우팅 방안을 제시하여 error 발생과 link fail에 대한 신속한 대처를 수행한다.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.9 no.2
• /
• pp.84-91
• /
• 2001

To investigate the aerodynamic characteristics of the on a road vehicle, experimenrs were performed at an Atmospheric Boundary Layer Wind Tunnel. The scaled model of an automobile with 1 : 3 scaling ratio was used. The Reynolds number based on the free stream velocity and model length was $7.93{\times}10^5$. The influence of crosswind to the stability of automobile was investigated by the pressure distribution measurements and flow visualization studies. with the variation of the angle of attack, the change in pressure coefficient depends highly on the flow separation regimes. The experimental and numerical results are compared and found to be in good agreements.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 2002.05a
• /
• pp.57-62
• /
• 2002

This study described the specification and configuration of developed fixed-base AHS (Automated Highway System) simulator fur the human factors researches, and its usability evaluation results after riding 120, 140, and 160kph automated driving speed. As the results, this study suggested the subjects' preferences and opinions about simulator and AHS configurations that would help to establish the AHS R&D plan and driver-vehicle/road interface design guidelines as the basic researches of the AHS human factors.

• Proceedings of the KIPE Conference
• /
• 2005.07a
• /
• pp.343-346
• /
• 2005

In this paper a power conditioning system suitable for the fuel cell powered off-road vehicle is proposed. The proposed system employs a Proton Exchange Membrane Fuel Cell stack combined with boost converter, a super capacitor module combined with hi-directional buck-boost converter, a 4-quadrant DC chopper and a permanent magnet DC motor. The momentary overload condition occurring during the motor starting is handled by the energy stored in the supercapacitor module. Also, the regenerative energy can be stored in the supercapacitor module by operating the system in either buck or boost mode. This capability gives the system designer the higher flexibility in designing the system and assures the lower cost of the system. The validity and feasibility of the proposed system is proven by the computer simulation.